This invention relates to a guidance system for agricultural equipment and more particularly to an adjustable calibration assembly for the guidance system.
Various agricultural machines utilize plant sensing wands mounted on the machine for sensing the position of the standing plants for various purposes. Typically, this sensing is for guidance purposes to provide a feedback signal to a machine guidance or positioning mechanism to assure proper positioning of the machine relative to a row of such plants. By way of example, such sensors and guidance systems may be utilized on cultivating equipment.
The sensing wands are affixed to a rotatable shaft. The shaft and wand may be biased to a predetermined angular position. As the wand contacts the crop, its angular position is adjusted whereby the angular position of the shaft reflects the sensed position of the crop relative to the machine.
Calibration of the sensing wands is necessary due to variations in crops and equipment. In previous units, the calibration was effected by adjusting a collar on the rotatable shaft. The set screw on the collar would be loosened and the angular relationship between the collar and the shaft would be adjusted to calibrate the wands. After obtaining the proper adjustment, the set screw is tightened while maintaining a precise angular relationship between the collar and the shaft.
The set screw and collar assembly is also used to calibrate the machine guidance or positioning mechanism which assures proper positioning of the machine relative to the row of plants. The guidance mechanism has an assembly which indicates the position of the guidance mechanism relative to the agricultural tractor on which the guidance mechanism is attached. Calibration of the guidance mechanism is necessary due to variations in crops and equipment.
This calibration or angular adjustment assembly becomes difficult to use for several reasons. The end of the set screw leaves indentations or scars on the surface of the shaft. After several adjustments, the surface of the shaft has several indentations. The set screw tends to move into one of the indentations when it is tightened which may not correspond to the desired adjustment. Therefore, these indentations make it difficult to perform precise adjustments.
Furthermore, it is necessary to perform precise adjustments because a small angular adjustment can significantly increase the performance of the guidance system. The set screw and collar assembly does not enable the operator to perform fine or precise adjustments of the assembly during calibration.
In addition, the set screw and collar assembly is not easily accessible to the operator and therefore, it is difficult for the operator to make the calibration adjustments.
One object of this invention is to provide an improved calibration device for a guidance system.
Another object of this invention is to provide a calibration device which will permit precise calibration of the sensing system.
Another object of this invention is to provide a calibration device which is less difficult to use and more accurate than prior devices.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and appended claims, and upon reference to the accompanying drawings.